OBJECTIVE To quantitatively evaluate the effect on decolonization of gram-negative bacteria(GNB) and carbapenem-resistant gram-negative bacteria (CRGNB) in water sinks of neonatal wards and compare the decolonization effects among the 500 mg/L, 1000 mg/L of chlorine-containing disinfectants and 3% hydrogen peroxide solution.

METHODS A total of 15 water sinks were chosen from West China Second University Hospital of Sichuan University as the research subjects, which were randomly divided into the 500 mg/L chlorine-containing disinfectant group, the 1000 mg/L chlorine-containing disinfectant group and the 3% hydrogen peroxide solution group. The bacterial colony counts of GNB and CRGNB as well as microbial diversity at the drain outlets were observed and compared before the intervention and after the disinfectants were continuously poured for 7 days.

RESULTS There were GNB and CRGNB colonized at the drain outlets of water sinks in the neonatal wards under the mode of regular rinsing with 500 mg/L of chlorine-containing disinfectant, with Pseudomonadaceae dominant. There were no significant differences in the bacterial colony counts of GNB/CRGNB, Alpha diversity (Shannon index) and Beta diversity (Bray-Curtis distance) among the three types of disinfectants after the intervention for 7 days.

CONCLUSIONS There are still large quantity of GNB and CRGNB colonized at the drain outlets of water sinks of neonatal wards after daily conventional treatment with 500 mg/L of chlorine-containing disinfectant. Neither the disinfectant with the concentration of chlorine increasing to 1000 mg/L nor 3% hydrogen peroxide solution can remarkably reduce the colonization or alter the microbial diversity. The optimal disinfection strategy should be formulated based on compound disinfectant, physical intervention and project reconstruction.